The present invention relates to an apparatus for bending a glass sheet supported on a ring mould, said apparatus comprising a press-bending station provided with thermally insulated walls, a press-bending tool above a ring-mould supported glass sheet in the press-bending station, as well as a mechanism for lifting and lowering the press-bending tool This type of glass-bending apparatus is disclosed in Patent publication U.S. Pat. No. 4 804 397. In that publication, the movements of a press tool for positioning and pressing are effected by means of a linkage driven through the station wall and the movements of such linkage require a relatively large through hole in the station wall. In addition, the mechanism is quite complicated and expensive and the accurate control of movements is difficult to obtain. The laid-open application EP 0338216 discloses a glass-bending apparatus, wherein a complicated moving mechanism for a press-bending tool is for the large part thereof located inside a bending station. However, the strength and proper function of complicated moving mechanisms are very difficult to secure at a glass-bending temperature.
An object of the invention is to provide an improved apparatus for moving or carrying a glass sheet press-bending tool in a bending station Particularly, the mechanisms capable of operating in the heat of a bending station must be structurally as simple as possible while the operation thereof should not require through holes that are difficult to seal.
This object is achieved on the basis of the characterizing features of the invention set forth in the annexed claims.
The invention can be applied e.g. to effect movements of such bending moulds that are described in the Applicants' earlier Finnish Patent applications 901601, 901602 and 901603.